Nikon confirms the 51 AF points in the D750 are narrower compared to the D810 - Nikon Rumors
アドバンストマルチCAM3500II AFセンサー Nikon D7200 : Came吉 写真館
D750 – Digital SLR Cameras - Nikon Singapore Pte Ltd
Does the 11 af points (Nikon D3400) vs the 39 af points (Nikon D5300) makes much difference when it comes to street, landscape, indoor and outdoor events, portrait, candid photography? - Quora
Nikon D850 camera autofocus (AF) coverage - Nikon Rumors